a) Field of the Invention
This invention relates to a colorant composition for lawns, and more specifically to a colorant composition which contains as a primary component a colorant effective not only for coloring lawns but also for promoting growth of the lawns and preventing aging of the lawns and which, when applied to color the lawns, the color so applied can remain for a long time and does not stain other articles through rubbing.
b) Description of Related Art
As lawns wither into a yellow or light brown color in-winter, colorant compositions with green or blue pigments contained therein have conventionally been sprayed to keep the lawns look green.
In these colorant compositions, organic pigments and/or dyes such as copper phthalocyanine blue pigments and copper phthalocyanine green pigments have been employed for the purpose of coloring alone.
These conventionally-employed pigments and dyes are however intended merely to color lawns at their surfaces, and no physiological effects for plants are observed on their coloring components themselves.
In these conventional colorant compositions, emulsions of acrylate ester resins, vinyl acetate resins, ethylene-vinyl acetate resins or the like or emulsions of water-dispersible polymers, such as synthetic rubber latexes, are also used as adhesives for fixing coloring components on turfgrass.
Incidentally, an emulsion of a polymer generally cannot form polymer films at temperatures lower than its film-forming temperature, so that a coloring component, especially a pigment cannot be fixed on turfgrass. When a colorant is sprayed in winter, the temperature is often so low that films cannot be formed with a pigment enclosed therein unless a polymer the lowest film-forming temperature of which is lower than the surrounding temperature, or example, is 5.degree. C. or lower is used.
In general, a polymer the lowest film-forming temperature of which is low is still soft and tacky even after formation into films, and is hence accompanied by a potential problem that they may be rubbed to stain shoes and clothing or at golf courses, to stain equipments such as balls and clubs.
With a view to improving the film-formability of aqueous emulsion polymers at low temperatures, film-forming aids are therefore often used in combination. Illustrative of film-forming aids are alkyl ethers and phenyl ethers of glycols and acetates of such ethers, and benzene or naphthalene solvents containing hydrocarbon groups. These film-forming aids cause no problem when employed industrially, but they are not suited for being sprayed over nature-oriented objects such as lawns and moreover, are also accompanied by a problem from the standpoint of odor.